Development of a Protein Crystal Formation System With a Superconducting Magnet

We have developed a protein crystal formation system, which can, on the ground, suppress convections, exerting magnetic forces on the solution including proteins. The protein formation system consists of a superconducting magnet system, protein crystallization cells, and observational equipment; the latter two devices are placed in the magnet bore. The superconducting magnet system includes two coil groups, each generating a magnetic field opposing in direction to each other. The product of magnetic flux density and its spatial gradient is proportional to the magnetic force and needs to be approximately 1400 T²/m in order to levitate water. The magnet is operated in persistent current mode. The crystallization cells are made of a transparent plastic on a plate. The experimental space and cells can be controlled between 4°C and 20°C. The observational equipment, which is a kind of periscope, enables in-situ observation of protein solution in high magnetic fields. In order to optimize experimental conditions, we have also carried out a simulation study based on a solution flow model.